import logging
from http import HTTPStatus
from copy import deepcopy
+from Crypto.Cipher import AES
+from base64 import b64decode, b64encode
+from osm_common.common_utils import FakeLock
+from threading import Lock
__author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
class DbBase(object):
- def __init__(self, logger_name='db', master_password=None):
+ def __init__(self, logger_name='db', lock=False):
"""
- Constructor od dbBase
+ Constructor of dbBase
:param logger_name: logging name
- :param master_password: master password used for encrypt decrypt methods
+ :param lock: Used to protect simultaneous access to the same instance class by several threads:
+ False, None: Do not protect, this object will only be accessed by one thread
+ True: This object needs to be protected by several threads accessing.
+ Lock object. Use thi Lock for the threads access protection
"""
self.logger = logging.getLogger(logger_name)
- self.master_password = master_password
-
- def db_connect(self, config):
+ self.master_password = None
+ self.secret_key = None
+ if not lock:
+ self.lock = FakeLock()
+ elif lock is True:
+ self.lock = Lock()
+ elif isinstance(lock, Lock):
+ self.lock = lock
+ else:
+ raise ValueError("lock parameter must be a Lock classclass or boolean")
+
+ def db_connect(self, config, target_version=None):
"""
Connect to database
- :param config: Configuration of database
+ :param config: Configuration of database. Contains among others:
+ host: database hosst (mandatory)
+ port: database port (mandatory)
+ name: database name (mandatory)
+ user: database username
+ password: database password
+ masterpassword: database password used for sensible information encryption
+ :param target_version: if provided it checks if database contains required version, raising exception otherwise.
:return: None or raises DbException on error
"""
- pass
+ raise DbException("Method 'db_connect' not implemented")
def db_disconnect(self):
"""
"""
raise DbException("Method 'replace' not implemented")
- def encrypt(self, value, salt=None):
+ @staticmethod
+ def _join_passwords(passwd_byte, passwd_str):
+ """
+ Modifies passwd_byte with the xor of passwd_str. Used for adding salt, join passwords, etc
+ :param passwd_byte: original password in bytes, 32 byte length
+ :param passwd_str: string salt to be added
+ :return: modified password in bytes
+ """
+ if not passwd_str:
+ return passwd_byte
+ secret_key = bytearray(passwd_byte)
+ for i, b in enumerate(passwd_str.encode()):
+ secret_key[i % 32] ^= b
+ return bytes(secret_key)
+
+ def set_secret_key(self, secret_key):
+ """
+ Set internal secret key used for encryption
+ :param secret_key: byte array length 32 with the secret_key
+ :return: None
+ """
+ assert (len(secret_key) == 32)
+ self.secret_key = self._join_passwords(secret_key, self.master_password)
+
+ def encrypt(self, value, schema_version=None, salt=None):
"""
Encrypt a value
- :param value: value to be encrypted
- :param salt: optional salt to be used
+ :param value: value to be encrypted. It is string/unicode
+ :param schema_version: used for version control. If None or '1.0' no encryption is done.
+ If '1.1' symmetric AES encryption is done
+ :param salt: optional salt to be used. Must be str
:return: Encrypted content of value
"""
- # for the moment return same value. until all modules call this method
- return value
- # raise DbException("Method 'encrypt' not implemented")
-
- def decrypt(self, value, salt=None):
+ if not schema_version or schema_version == '1.0':
+ return value
+ else:
+ if not self.secret_key:
+ raise DbException("Cannot encrypt. Missing secret_key", http_code=HTTPStatus.INTERNAL_SERVER_ERROR)
+ secret_key = self._join_passwords(self.secret_key, salt)
+ cipher = AES.new(secret_key)
+ padded_private_msg = value + ('\0' * ((16-len(value)) % 16))
+ encrypted_msg = cipher.encrypt(padded_private_msg)
+ encoded_encrypted_msg = b64encode(encrypted_msg)
+ return encoded_encrypted_msg.decode("ascii")
+
+ def decrypt(self, value, schema_version=None, salt=None):
"""
Decrypt an encrypted value
- :param value: value to be decrypted
+ :param value: value to be decrypted. It is a base64 string
+ :param schema_version: used for known encryption method used. If None or '1.0' no encryption has been done.
+ If '1.1' symmetric AES encryption has been done
:param salt: optional salt to be used
:return: Plain content of value
"""
- # for the moment return same value. until all modules call this method
- return value
- # raise DbException("Method 'decrypt' not implemented")
+ if not schema_version or schema_version == '1.0':
+ return value
+ else:
+ if not self.secret_key:
+ raise DbException("Cannot decrypt. Missing secret_key", http_code=HTTPStatus.INTERNAL_SERVER_ERROR)
+ secret_key = self._join_passwords(self.secret_key, salt)
+ encrypted_msg = b64decode(value)
+ cipher = AES.new(secret_key)
+ decrypted_msg = cipher.decrypt(encrypted_msg)
+ unpadded_private_msg = decrypted_msg.decode().rstrip('\0')
+ return unpadded_private_msg
def deep_update_rfc7396(dict_to_change, dict_reference, key_list=None):